Add try.sh to 1985/august

The script has fun with reversing bits too through rev(1) (if
installed).

The script calls primes.sh even if primes(6) is not installed as that
script will check that it's installed and will tell one where to get it
if it's not. It only uses the default value, however, so primes.sh is
still shown in the README.md file.

1985/august/README.md

@@ -15,7 +15,7 @@ make all
 ### Try:
 
 ```sh
-./august | head -n 10
+./try.sh
 ```
 
 If you have the `primes(6)` tool (sometimes part of [BSD
@@ -27,6 +27,10 @@ what of the output in the first `N` (say `15` or `25`) lines are primes:
 ./primes.sh 25
 ```
 
+Note that `try.sh` will run this script anyway, telling you where to get
+`primes(6)` if you don't have it installed, but it will only run with the
+default value of 15, rather than trying several different values.
+
 
 ## Judges' remarks: